Piling section



Dec. 8,1936. BQRBERG 2,063,293

FILING SECTION Filed April 6, 1935 liwenfar: /400/ F BO E e Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to piling sections that are used for constructing docks, coffer dams, retaining walls, etc., and more particularly to the interlock devices which maintain them in assembled relationship.

The piling sections of the prior art, and particularly those employing what is known asthe tongue and groove type of interlock, are frequentlysubjected totwisting stresses, either during the driving thereof, or after they are driven, which tend to rotate adjacent piling sections of their interlock and thereby break them apart or deform the wall of which they are part. This tendency of the interlocked sections to rotate on their interlocks is therefore often undesirable, and is due to the necessity of maintaining relatively wide tolerances while they are being rolled in the mill.

According to the prior art, the interlock devices of these piling sections have been rolled within close tolerances, and certain planes thereof have even been machined in order to procure a close fit and consequent reduction in flexibility of the interlock.

It is among the objects of the present invention to provide a novel interlock device for piling sections which when assembled is comparatively inflexible when subjected to twisting stresses, and one which at the same time may be cheaply and easily rolled in accordance with acceptable mill tolerances.

The foregoing and further objects will be apparent after referring to the drawing, in which:

Figure 1 is a fragmentary plan disclosing the interlock device of the invention as employed on two piling sections which are in assembled, or interconnected, relationship.

Figure 2 is a view similar to Figure 1, but disclosing the manner in which the device of the invention is intended to function.

Referring more particularly to the drawing, the numerals 2 and 3 designate the adjacent ends of the body portions of two piling sections which are to be connected in accordance with well known practice. The piling sections 2 and 3 may be of any desired shape, and are provided on each of their longitudinal edges with an interlock area which comprises one element of an interlock device. That is to say, one longitudinal edge of one piling section, by way of example, is preferably provided with a tongue portion, while its opposite longitudinal edge is provided with a groove portion which conforms thereto.

Accordingly, the interlock area of the piling section 2 is designated at 4, and comprises in general an enlarged portion 6 having walls I and 8 which converge into the base of a laterally extending and substantially triangularly shaped tongue 9.

The interlock area of the piling section 3 is designated at 5 and has a groove opening 10 which conforms to, but is substantially larger than, the tongue -9 of the interlock area 4. This groove [0 effectively receives the tongue 9 and retains it by means of a pair of overhanging fingers l2 and [3 which are adjacent the convergent walls 1 and 8, respectively, of the enlarged portion 6 of the interlock area 4. The finger I3 provides a wall I4 which is substantially parallel to the wall 8 of the enlarged portion 6 of the interlock area 4.

The ideal, or theoretical, disposition of the tongue 9 in the groove I0 is shown in Figure 1 with the axial and transverse center lines of both being represented by the lines a. and b, 0 respectively. This ideal, or theoretical, disposition cannot be maintained because of twisting stresses, or bending moment which may take place in the direction of the curved arrow of Figure 2. When subjected to stresses in this 25 direction the tongue 9 on the interlock area 4 will naturally tend to move out of the groove ID in the interlock area 5, but resistance is established by the overhanging finger l2 at the point of contact c. This resistance, however, is not 30 sufiicient if an increased lever arm accrues from excessive tolerance or, for example, the lateral deflection of the piling section 2 in the direction of the dotted arrow of Figure 2. Under these circumstances the tongue 9 will contact the 35 finger [2 which overhangs the groove I 0 nearer its extremity with the result that there is a great likelihood on the part of the finger to spring, or become bent, to such an extent as to cause detachment of the elements. This condition is il- 40 lustrated in dotted lines in Figure 2, wherein d and 2 represent the axial and transverse center lines, respectively, of the tongue 9. From this view it may be seen that the point of contact of the tongue is occupying the deleterious position mentioned, as shown at 1.

According to the teaching of the present invention, this unfavorable condition is completely obviated by providing an abutment shown in the drawing as a lug [5 on the wall l4 of the interlock area 5 and a cooperating abutment provided by a recess IS on the wall 8 of the interlock area 4. This lug I5 is constructed and arranged to seat in the recess 16 upon the slightest partial rotation, or lateral deflection, of either of the piling sections 2 and 3 in the direction of the outside face of the piling. It will be explained that the lug 15 provides an abutment which lies at one side of the axial center line a--a and has a wall which faces transversely inward towards said axial line, while the recess l6 provides an abutment located at the same side of the axial center line a-a. as the lug or abutment l5, and has a wall facing transversely outward and away from the axial center line aa. These two abutments are mutually disposed so that the said walls thereof will come into contact upon slight rotation of the piling sections 2 and 3 on their interlock and thereby limit rotation of either or both of the piling sections on the interlock. This not only prevents further partial rotation, and lateral deflection, but also the excessive movement of the tongue 9 out of the groove III. The lever arm is therefore reduced, as the point of contact of the tongue 9 on the finger I2 is maintained at the point 0 of Figure 2.

In this manner, the piling sections 2 and 3 are maintained against detachment due to twisting stresses in a very inexpensive fashion, as no consideration to reduction of tolerances need be given to the tongue 9 and groove 10 during rolling. The abutments I5 and I6 may be easily rolled and may be used on either side of the axial center line a of the interlock.

While I have shown and described one specific embodiment of my invention, it will be understood that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of my invention, as defined by the following claims.

I claim:

1. In combination with piling sections employing an interlock device of the tongue-and-groove type, of means entirely extraneous to said interlock device for limiting the rotation of the sections when in assembled relationship, said means comprising a lug on one of said assembled sections, the other of said assembled sections having a recess to receive said lug.

2. Piling comprising sections connected by an interlock device of the single tongue-and-groove type and also provided with means extraneous to said interlock device for limiting rotation of the piling sections on their interlock connection when in assembled relationship, said means comprising a lug on one of said piling sections extending towards the other piling section from a point on said one section located in front of the interlock parts thereof and adapted to engage in a recess formed in the other section at a point therein located in rear of the interlock parts thereof.

ADOLF BORBERG. 7 

